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<br />I .~ <br />i <br />~I <br />I <br />~I <br />~~ <br />Boulder Cov{ity - 5. ~ - <br />MI HI HG & MIRE METHODS - Coatin. <br />planed in auoh a manner that --they Dan be operated from with- <br />out. <br />The method of ore eatraotion ie overhand atoping and <br />drifting. IIo hand drilling is done and Dtandard maohine dril <br />are employed. - ' <br />The method employed Yor timbering is poste and Daps in <br />the tunnel and atolls covered with lagging in other parts oY <br />the workings. The tiabere are prepared by hand from pine and <br />red spruce, are in good condition and auYYioient to insure <br />safety. <br />Chntea are loaded by hand and gravity. <br />Dnderground training is done with mules and steel oars <br />and the trackage is li3" gunge and L0~ T rails. <br />llrainsge and ventilation are natural and the eanitaxy <br />conditions are good. IIo noxious gases are met with and all <br />old timbers and debris have been removed Yrom underground so <br />ae•raork has progressed. <br />Carbide leaps are used Yor lighting underground. <br />S T A T I S T I C S, <br />Grose tonnage not given. <br />Average tonnage per aonth, 1,000. <br />Average value of ore per ton, X10. <br />Cost per ton mining of ore, v°2.b0. <br />Cost per ton tramming of ore, ---- <br />Co et per ton treatment of ore, 31.b0. <br />Total number oY Yeet in shafts, 1,100. <br />" " " " " tunnels, 3,200. <br />" " " " " drifts, 2,000. <br />Average ooat per month for eleatrio power, $b00. <br />" timber, g60. <br />" '" steel, $16. <br /> <br /> <br /> <br />